Rove beetles of the genus Quedius (Coleoptera, Staphylinidae) of Russia: a key to species and annotated catalogue

Abstract This paper is the first inventory of the fauna of the rove beetle genus Quedius in the Russian Federation. It provides an annotated catalogue of 88 species of Quedius currently recorded from Russia, based on several collections and a critical evaluation of all earlier published records. All species are listed with a summary of their overall distribution and bionomics. Species distributions within Russia are given as lists of regions where they occur with references to the respective source collections or publications which any record is based on. For that, the territory of Russia is divided into 40 regions that mostly follow the administrative division of the country. The annotated catalogue is supplemented by a well-illustrated identification key to all species and a concise checklist in form of an easily visualized table. Quediusfusus Cai & Zhou, 2015, Quediushumosus Solodovnikov, 2005, and Quediuslundbergi Palm, 1973 are recorded from the territory of Russia for the first time. Based on an analysis of literature and available material, records of Quediuscincticollis Kraatz, 1857, Quediushumeralis Stephens, 1832, Quediusmaurorufus (Gravenhorst 1806), Quediusnemoralis Baudi de Selve, 1848, Quediusnigrocaeruleus Fauvel, 1876, and Quediuspicipes (Mannerheim, 1830) from Russia are considered doubtful. The distribution of Quediusbrachypterus Coiffait, 1967, described from the ‘Caucasus’, remains ambiguous and its presence in Russia is unlikely. The identity of Quediusfulvipennis Hochhuth, 1851 from ‘Dahuria’ remains unknown, pending examination of the type material. For Quediuscitelli Kirschenblatt, 1933 a lectotype is designated. For that species and Q.sofiri Khachikov, 2015 illustrations of the aedeagi are provided for the first time. The paper stresses the currently poor state of knowledge of the Quedius diversity in Russia and provides a platform for its improvement, which should begin with a large-scale sampling program, especially in Siberia and Far East.


Introduction
With more than 700 species (Herman 2001;Schülke and Smetana 2015) the mainly Holarctic genus Quedius Stephens, 1829 is one of the largest among rove beetles (family Staphylinidae) and insects as a whole. Quedius are very common inhabitants of the forest leaf and log litter, but they can also be found in other ground-based debris of open landscapes. Some species occur in mammal and bird burrows and nests, in the nests of ants and other wasps, or they are highly adapted to hypogean microhabitats. The species of Quedius strongly vary in their landscape and microhabitat preferences, ecological tolerance and, as a result, in the types of their distributions. All these characteristics make Quedius commonly encountered beetles and a good model for ecological and biogeographic studies.
Almost the entire diversity of Quedius is confined to the Palearctic region (Schülke and Smetana 2015;Smetana 2017) where the largest area is covered by the territory of the Russian Federation. Historically, the main focus of explorations of the Palearctic fauna, including studies of Quedius, has been its European part, while the rich and unique faunas of Asia were studied only patchily or remained unexplored. In the last decades we have witnessed a growing interest in the Chinese Quedius (Smetana 2017) and, recently, the Middle Asian fauna has been revised (Salnitska and Solodovnikov 2018a, b). With all this progress, the Quedius of Russia became a very obvious knowledge gap. As can be seen even from patchy recent publications (Solodovnikov and Hansen 2016;Salnitska and Solodovnikov 2018a;Smetana and Shavrin 2018), the geographically vast and diverse Russia hides numerous Quedius species which have not been recorded yet, or are even new to science. To facilitate the badly needed exploration of Russian Quedius, we here make a synthesis of the current knowledge of this group within the Russian borders. It aims to structure and summarize all existing literature and the main collections of Russian Quedius specimens to assess the fauna, define the largest knowledge gaps and provide an easy platform for further research.
Russia is a country stretching through a large and extremely diverse geographic area (Fig. 1) that includes diverse biomes from arctic deserts to subtropics. Even though a considerable part of Russia is located within the less biologically diverse polar or boreal regions, its overall species diversity is high because of the multiple terrestrial ecosystems, landscapes and habitats meeting here.
With respect to Quedius, very little is known about the Russian fauna. It is very difficult to initiate and advance studies in this direction because even the existing scarce taxonomic and faunistic literature relevant to Quedius in Russia is very fragmented, incomplete and, at most, applicable only to smaller regions of the country. So far, reliable work can be done only by somebody with many years of experience. There is not a single publication which could serve as an easy 'kick start' for taxonomic or faunistic work on Quedius in Russia by the broader community of entomologists. All existing catalogues that cover Russia provide little detail specifically for its territory. For example, the catalogue of rove beetles of the former USSR and adjacent regions in Tikhomirova (1973), a breakthrough for its time and listing 177 species of Quedius, is now greatly outdated in terms of taxonomy and coverage. The important Staphylinidae catalogues for the Palearctic region (Schülke and Smetana 2015) or the entire world (Herman 2001) consider Russia only very superficially. For example, in Schülke and Smetana (2015) the territory of Russia is subdivided only into six very large regions and the distribution of each species looks like an enumeration (and thus a very rough outline) of these regions without their underlying literature records. Although Herman (2001) provided an extremely helpful summary of all main references from 1758 to 2001 for each species listed in his catalogue, information relevant for species in Russia is incomplete there. It is even more difficult to identify material collected in Russia. There were only two incomplete and now greatly outdated keys for the Quedius fauna of the European part of Russia: one with only eleven species (Jacobson 1905;reproduced and updated in Bogdanov-Katkov, 1930) and the other with 50 species (Kirshenblat 1965). Otherwise, identification of Russian Quedius specimens could be attempted with the aid of modern keys for Central European fauna (Solodovnikov 2012b), the outdated monograph of the West Palearctic Staphylinidae (Coiffait 1978), or the recent monograph of Quedius of China (Smetana 2017). Needless to say that none of these keys can really work for the Russian fauna as a whole because at most one can key out only widespread species or those that occur in the immediate neighborhood to the geographic coverage of these keys. The absence of good synoptic collections of Quedius that would be distributed in Russia, or at least accessible at the main Russian institutions, contributes to the impediment. All this motivated us to compile the present work, which is an identification key and an annotated catalogue of all species of Quedius that we have found in the fauna of Russia thus far, based on an exhaustive literature survey and examination of the main collections herein and abroad.

Materials and methods
Our publication is based on literature data and examination of specimens from several collections abbreviated as follows:

CNC
Canadian National Collection, Ottawa, Canada (A Brunke)

ISEA
Institute of Systematics and Ecology of Animals, Siberian Branch of the Russian Academy Sciences, Novosibirsk, Russia (R Dudko)  To gather original distributional and reference data for this publication we used a custom made database implemented in Microsoft Access 2010. Our publication consists of three interconnected parts: 1) identification key to all Quedius species that occur in Russia; 2) annotated species list arranged by subgenera and alphabetically within each subgenus; and 3) a brief summary of distribution, abundance and source of data for each species in Russia in tabular format, with species arranged alphabetically across the entire genus.

Russia and its division for the catalogue
The Russian Federation ( Fig. 1) 185N, 47.782E] (Dagestan Republic) in the south. Kaliningrad Province, including its numerous small islands in the Baltic Sea, is the westernmost enclave separated from the rest of the country by Lithuania, Latvia, and Estonia. While the Crimea Republic is separated from the rest of Russia by the south-western part of Ukraine and the Kerch Strait. From north to south, Russia covers several climate zones from the arctic to subtropics. From west to east it is extended from the Baltic Sea through Siberian plains and Far East mountains to the Pacific Ocean. Russian terrain consists of very diverse forms of relief ranging from high mountains such as Caucasus with Elbrus Mountain as the highest point in Russia at 5642 m, through Ural, Altai, Sayan, Sikhote-Alin, Verkhoyansk, and Chersky ranges, to the plains and lowlands such as European, west Siberian and north Sakhalin plains, or north Russian, Pskov, Cis-Kuban, Cis-Ilmen, Abyisk lowlands, or Kuznetsk Depression, and others.
Finding a system of subdivision for such a large and diverse area as Russia that is suitable for cataloguing purposes is complicated. Normally it is better to visualize species ranges via some biogeographic division reflecting natural geographic units or landscapes (Kryzhanovsky et al. 1995). Such an approach is feasible in the case of well-studied faunas, with clear distributions and bionomics of the species, as well as some widely agreed biogeographic scheme. Unfortunately, rove beetles and Quedius in particular are very poorly explored, while a widely agreed upon and detailed biogeographic division of Russia is even more of a problem. In our case, the use of political administrative regions with unambiguous borders, standardized across various maps, is a viable solution. Additionally, records from local faunistic publications are usually restricted to such regions. Therefore, accepting them for our catalogue also simplifies the inventory of these publications. However, political divisions, especially in Russia, comprise units that are not always geographically homogeneous and may consist of very different, sometimes contrasting geographic regions. A large river, a mountain ridge, or another natural barrier may cut a certain large administrative region as the Lena River does in Yakutia (Sakha) Republic, or Kulunda steppe in Altai Territory. On the contrary, some geographically uniform areas may be divided between several administrative regions such as the Ural Mountains, stretching through Yamalo-Nenets and Khanty-Mansi Autonomous districts, Tuymen, Sverdlovsk, and Chelyabinsk provinces. Moreover, the denser populated European part of Russia is fractured into numerous and small administrative regions such as Orel Province or Mordovia Republic, whereas poorly populated Siberia consists of very large regions such as Yakutia (Sakha) Republic or Evenk Autonomous District.
To overcome these problems, we here divide Russia as in the Catalogue of Lepidoptera of Russia (Sinev 2008), which is mainly based on administrative political regions with minor amendments following geographic considerations (Fig. 2). In particular, groups of smaller geographically similar regions of European Russia are merged together, while some Siberian regions are subdivided in accordance with geographic barriers. For the purposes of our catalogue, the composition of some administrative regions was changed according to geography, as follows: Arkhangelsk Province is divided into two regions, one consisting of Nenets Autonomous District with the Novaya Zemlya archipelago and the other covering the rest of its continental area. Tyumen Province is divided in two regions, west and east of Tobol and Irtysh rivers, respectively. Altai Territory is divided into Kulunda steppe and the rest. Krasnoyarsk Territory, apart from Taymyr and Evenk Autonomous Districts, is divided into two regions, one north and one south of Sym River. Similarly, Khabarovsk Territory is divided in two regions, one north and one south of Uda River. Yakutia Republic is divided in three regions, North-Western, North-Eastern and Southern Yakutia, based on the Verkhoyanskiy Range watershed and the Rivers Vilyuy and Aldan, respectively.
As a result, the Russian Federation here is divided into 40 regions abbreviated and listed alphabetically as follows. Numbers correspond to the respective position of the regions in Table 1 where they are arranged according to their location in Russia, from north to south and from west to east:

History of the study of Quedius of Russia
The first mentions of species of the genus Quedius from an area that included the territory of modern Russia belong to Hochhuth (1849Hochhuth ( -1862 who published several works on the fauna of the Caucasus (1849) and "Russlands" (1851, 1862). The first descriptions of new species from the territory of Russia were confined to the unique and rich fauna of the north-western Caucasus (Eppelsheim 1878a(Eppelsheim , b, 1889Roubal 1911). Among other pioneering studies, Fauvel (1875), Eppelsheim (1886Eppelsheim ( , 1887, Bernhauer (1902), and Roubal (1914Roubal ( , 1929 described new species from Siberia and the Russian Far East.

Taxonomy
The subdivision of the genus Quedius into subgenera is used here according to Schülke and Smetana (2015). It is noteworthy to mention that the genus Quedionuchus recently reinstated to this level (Brunke and Solodovnikov 2013) is not included in this catalogue. Within subgenera, we list species alphabetically. Since the territory of Russia is very extensive, it is impossible to use any species groups developed only for local faunas from adjacent countries such as China (Smetana 2017).
At the species level, there are a number of taxonomic problems pending more detailed studies as well. For example, Quedius umbrinus displays very strong morpho-logical variation suggesting a complex of more than one species. On the other hand, species limits are not clear among some described species, to mention Q. sublimbatus and Q. arcticus pair, or the Q. boops-group as examples. In case of Q. sublimbatus and Q. arcticus, we follow their conventional synonymy. Our accepted concept of Quedius boops, Q. boopoides, and Q. paraboops also needs further study. These three species are  indistinguishable from each other by characters of external morphology. Genitalic differences are subtle, subject to variation and, together with geographic distribution, are interpreted here as follows. Two species, Q. boops and Q. boopoides, occur sympatrically from Europe to Siberia, but Q. boopoides gradually becomes rare from the west to the east of its range, which does not reach the Far East. Meanwhile, Q. boops is present in the Far East, with its easternmost record known from the Lower Amur region. At the same time, Q. paraboops is known only from Siberia and Far East, but its western form that occurs in Krasnoyarsk and Tuva regions appears as a gradual transition between this species and Q. boops. Future examination of a larger amount of material using rigorous methods of molecular and morphometric species delimitation should bring more clarity about species limits in the Q. boops-group. Other species of the Russian fauna also pose various taxonomic problems, perhaps of a lower severity. In those cases some assumptions or preliminary conclusions are discussed in the respective 'Notes' section. In general, we deliberately avoided any taxonomic changes and nomenclatural acts here, pending their proper justification and implementation in the separate publications.

Identification keys
These are traditional dichotomous keys that also include a succinct summary of the most important diagnostic and biological features for each species. Often distributions or bionomics may be as helpful as morphology, especially for identification of closely related species. The overall structure of the key and some aedeagus illustrations are adopted from Solodovnikov (2012). Species whose presence in the Russian fauna is strongly ambiguous are placed in square brackets. Aedeagus (     Eyes small and flat, distinctly shorter than temples. Aedeagus ( Fig. 11L-N): (in lateral view) apex of median lobe broad and distinctly protruding over apex of paramere (Fig. 11M); paramere on underside with about six or less sensory peg setae in each of two longitudinal rows (Fig. 11N)  Larger species, body length 6.8 mm. Aedeagus as in Fig. 11U Microsculpture of head and pronotum consisting of isodiametrical meshea, never of waves and micropunctation. Head and pronotum dull, not glossy. Head dark brown, pronotum reddish-brown to brown with paler sides; elytra, appendages and apical parts of abdominal tergites reddish to pale brown. Aedeagus as in Fig. 12A-C. Body length 9.0-10.0 mm. Widely distributed in the Europe and European part of Russia, reaching south-western Siberia. Usually associated with mole nests (Potockaja 1967;Osella and Zanetti 1975;Nowosad 1990 Head narrow, pronotum with distinctly pronounced posterior angles and lateral contours strongly narrowing anteriad. Aedeagus Body testaceous brown to blackish, pronotum and especially elytra and apical margins of abdominal tergites often paler than rest of the body (Fig. 5F). Aedeagus as in Fig. 12J  17 Infraorbital ridges (head in latero-ventral view) well developed at base only, not reaching base of mandibles. Aedeagus distinctly asymmetrical ( Fig. 13D-F). Body pale brown; elytra mostly yellowish with darkened lateral hind angles and, sometimes, also darkened along suture. Body length 6.   Aedeagus: (in lateral view) subapical tooth distinct as such, median lobe apicad of this tooth not resembling an axe blade (e.g., Fig. 15E, H, N (in parameral view) median lobe narrower, with narrow but rounded apex; paramere gradually narrowing anteriad, not narrower in middle part, underneath with rows of peg setae converging apicad (Fig. 15M, O). Piceous to piceous black, pronotum and elytra sometimes more or less brownish. Appendages yellowish-brown (Fig. 6E). Body length 5.0-6.2 mm. Circumpolar species, common in the northern parts of Eurasia and North America. In Russia, widespread in the north, but also can be found  16O); (in parameral view) paramere with rows of sensory peg setae extended along parameral margins, slightly diverging from sides basad (Fig. 16N 17O); (in lateral view) median lobe with subapical tooth situated far from its apex (Fig. 17N) Elytra as long as and slightly longer than pronotum (Fig. 7D). Aedeagus: (in parameral view) apex of median lobe not pointed, underside of paramere with sensory peg setae forming thin and long rows (e.g., Fig. 17R); (in lateral view) median lobe with ventral tooth situated close to its apex (e.g., Fig. 17Q Larger species (Fig. 7E), body length 8.0-8.5 mm. Aedeagus (Fig. 18A-C): (in lateral view) median lobe with sharper apex (Fig. 18B); (in parameral view) paramere underneath with two rows of peg setae closer to parameral midline than to lateral margins, convergent (Fig. 18C) Larger species with body length 8.0-11.0 mm. Body brown to blackish; elytra from completely dark to completely pale but most commonly pale with more or less darkened margins (Fig. 8B). Aedeagus (Fig. 18S-U): (in parameral view) apex of paramere reaching or nearly reaching apex of median lobe, paramere underneath with short and broad groups of densely spaced peg setae (Fig. 18S

Annotated catalogue of species of Quedius of Russia
This annotated catalogue provides details about identity, general distribution, and bionomics of every species. Complete synonymies for each species can be found in the catalogue of Herman (2001). Here we list only synonyms proposed later and not accounted in that world catalogue. In brief format all synonyms published before 2015 can be also found in the Palaearctic Catalogue (Schülke and Smetana 2015). Species distributions within Russia are given in the form of abbreviated regions from which a given species was recorded with reference to the respective literature or collection source. For easier navigation, abbreviations of the regions are listed alphabetically for each species. In cases where it was necessary but impossible to establish * Externally, Q. lateralis, (aedeagus as in Fig. 18V-X), may fit here except for its different coloration of elytra, which are dark with yellow epipleura. The presence of Q. lateralis in Russia is questionable, for details see notes for Q. suramensis in the Annotated catalogue section.]    exact localities for species records based on old references, we simply cited these papers, with the original data given verbatim, where available. One catalogue to which we also refer here (Silfverberg 1992) provided species distributions as a summary list of larger territories, which do not coinside with the regions we use here. Regions in Silfverberg (1992), namely Karelia Republic, Murmansk province, left banks of Onega and Kena rivers in Arkhangelsk province, northern part of Andomian upland, and right banks of Svir and Neva rivers in Leningrad province, are here referred altogether as 'northern part of European Russia'. Species whose presence in the Russian fauna is strongly ambiguous are given in square brackets, i.e., in the same way as in the keys above. Species whose taxonomic identity is ambiguous and need a revision are marked with an asterisk *. This species is widely distributed in Japan (Shibata 1984) and known from the Russian Far East from an unspecified locality. There are no published data on its bionomics. Russia: unspecified locality in the Far East (Schülke and Smetana 2015). Fig. 9N-P According to published records, this species is restricted to the Kamchatka peninsula. Its bionomics is currently unknown. Russia: KAMCHATKA (Smetana 1976(Smetana , 1978b.

Quedius (s. str.) balticus Korge, 1960
Figs 5D, 10U-X This species is distributed in the northern and central regions of Europe where it occurs in various wet ground-based debris, along sea and lake shores. It is considered halophilous or at least tolerant to habitats with high salinity (Coiffait 1978;Solodovnikov 2012b). In Russia it is known only from a few literature records for the southern regions of its European part.

Quedius (s. str.) curtipennis Bernhauer, 1908 Fig. 9T-V
Quedius curtipennis is considered to be a rather common, polytopic and widely distributed species that is collected from various ground based microhabitats across the entire West Palearctic (Herman 2001). It was also introduced to North America (Smetana 1971(Smetana , 1978a(Smetana , 1990. In Spain it was recorded from a cave (Outerelo et al. 1998). However, as stated in Salnitska and Solodovnikov (2018b), its actual distribution, especially outside Europe, requires revision because this species can be easily confused with Q. fuliginosus (see below). The data summarized here suggest that Q. curtipennis is widespread in the European part of Russia.

Quedius (s. str.) fuliginosus (Gravenhorst, 1802) Fig. 9Q-S
This is one of the most common species of Quedius distributed throughout the entire West Palearctic east to Middle Asia (Salnitska and Solodovnikov 2018b). Its record from Northern China (Horion 1965) is obviously erroneous, because in the latest revision of the Chinese Quediina (Smetana 2017) the subgenus Quedius s. str. was not found in that country at all. In Russia, Q. fuliginosus appears to be widely distributed in its European part and extends further east reaching Northern Yenissey and Krasnoyarsk regions. The species is polytopic and can be found in forests and open landscapes, usually in leaf and log litter and different kinds of ground debris (Solodovnikov 2012b); it has been recorded from mole nests (Nowosad 1990), from Polyporus squamosus fungi (Semenov et al. 2015a) and from ant nests (Goreslavets 2010(Goreslavets , 2016. Because of the strong similarity with Q. curtipennis (see above) its literature records from Russia need careful checking.

Quedius (s. str.) levicollis Brullé, 1832
Figs 5B, 10A-D Quedius levicollis is widespread in the West Palearctic, from Europe to the Middle East (Faldermann 1835;Horion 1965;Smetana 1967Smetana , 1978a and North Africa (Fauvel 1902;Gridelli 1924). The species becomes more rare towards the north. In Russia, it is not common and known only from a few regions of its European part. The species is distinctly thermophilous, avoiding montane areas and preferring open landscapes, especially sandy soils. It can be found in various ground debris on shores or even under seaweeds on beaches (Solodovnikov 2012b); it was also recorded from caves in Sardinia (Bordoni 1982).

Quedius (s. str.) molochinus (Gravenhorst, 1806)
Figs 5E, 10M-P This is one of the most common Quedius s. str. species broadly distributed in the West Palearctic and introduced to North America (Herman 2001). Southern Palearctic records need revision because of the confusion with Q. meridiocarpathicus (see above).
In Russia, it is also widely distributed, reaching Krasnoyarsk and North Yenissei regions in the east. The record from Zabaikalsky Territory (Shavrin 2000) needs confirmation due to its isolation from the reliably known distribution area. It can be found in leaf litter and various wet ground debris; it was also recorded from a Talpa europaea nest (Osella and Zanetti 1975), and in association with ants (Goreslavets 2016). Based on the material examined here from the Ural Mountains, the species can be found at rather high elevations, up to 1548 m.
Russia: BURYAT (Shavrin 1998 The species was hitherto known from Northern Europe (Korge 1961;Palm 1962;Coiffait 1978). Records from Czech Republic, Slovakia, southern Poland and Germany (Smetana 1993;Majzlan et al. 1997;Boháč et al. 2006;Wojas 2006) are obviously misidentifications of the very similar Q. unicolor. In Russia, it is known only from the Northern European region. Quedius subunicolor can be found in moss in wet habitats (Palm, 1963).

Quedius (s. str.) sundukovi Smetana, 2003 Figs 5C, 10E-H
Quedius sundukovi is a clearly brachypterous species with a surprisingly wide distribution. In Russia, it is known from an extensive area from the Far East to south-eastern Siberia. A single record exists from the Altai Mountains in Kazakhstan (Salnitska and Solodovnikov 2018b). The species inhabits regular leaf litter of broad leaved, coniferous, or mixed forests, where usually it can be found in talus-associated debris or moss on the ground. Based on the material examined here, it is also recorded from rather high elevations, up to 2000 m.

*Quedius (Microsaurus) amplissimus Bernhauer, 1912
This species has not been studied since its original description, which was based on the single female from Crimea "der Umgebung von Sebastopol" (Bernhauer 1912). The author indicated that the species was similar to Q. brevicornis. Gridelli (1924) placed this species near Q. fulgidus and basically repeated the notes from original description. Jarrige (1971) recorded Q. amplissimus from Iran based on the single female without any comments in support of his identification. From the high quality photos of the female holotype available from the Field Museum online beetle type database (FMNH, 2018), one can see that Q. amplissimus may be conspecific with Q. brevicornis. Fig. 11U, V Quedius amurensis was recently described from Amur Province (Smetana and Shavrin 2018). The type material was found in leaf litter and mosses at a swampy site and in mixed forest (Smetana and Shavrin 2018).

Quedius (Microsaurus) brevis Erichson, 1840
Figs 6A, 12O-Q The species is widely distributed in the Palearctic from Europe (Solodovnikov 2012b) to the Russian Far East. In Russia, it is known from sparse records through its whole territory. Quedius brevis is a myrmecophilous species confined to the nests of ants mostly of the genus Formica (Grimm 1845;Janák & Vysoky´ 1992) or sometimes Lasius (Smetana 1958).
Russia: CN EUR RU (Semenov 2009;Semionenkov et al. 2015; NHMD; ZIN); EUR S-TAIGA RU (Dedykhin et al. 2005;ZIN); IRKUTSK PROV (cSha, ZIN); LWR AMUR (cRyv); MDL VOLGA (Goreslavets et al. 2002;Shulaev and Bogdanov 2008;Goreslavets 2010Goreslavets , 2016Goreslavets , 2016bSemenov et al. 2015); NW EUR RU (Seidlitz 1875;Poppius 1908;Savelyeva and Dolgin 2009;ZIN); S YAKUT (cRyv); VOLGO-DON (ZIN); unspecified localities: 'Russlands' in Hochhuth (1862); northern part of European Russia (Silfverberg 1992). Fig. 12R-T The species was hitherto known only from the type locality Adun-Tshelon Mountain Ridge in Zabaikalsky Territory (Kirshenblat 1933). It was collected in the burrow of the ground squirrel Spermophilus dauricus Brandt, 1843. Boháč (1988 illustrated an aedeagus of the specimen that he claimed to be the type of Q. citelli. Kirschenblatt (1933) did not specify the number of the type specimens and from his description it is only clear that he had more than one specimen. We were able to find one male and two female specimens with the labels "Adun-Tshelon plemchoz. Zabaik. Bytshkov VIII.929/ burrow of ground squirrel/ Quedius citelli sp. nov. Kirschenblatt det" which are undoubtedly syntypes of Q. citelli. However, the male syntype was intact (not dissected by Boháč) and our examination of its aedeagus showed that its structure (Fig.  12R-T) is completely different from the description and illustration provided by Boháč (1988). Potentially, Boháč (1988) had dissected another syntype specimen which we did not find and in this case, two species would be hiding under Q. citelli. Alternatively, he has illustrated the aedeagus of another species based on some other material.

Quedius (Microsaurus) citelli Kirschenblat, 1933
Lectotype designation: to avoid confusion and fix the identity of Q. citelli, here we designate one male syntype as a lectotype rendering two mentioned female paralectotypes.

Quedius (Microsaurus) edmundi Coiffait, 1969 Fig. 13G-I
Quedius edmundi is endemic to the North-Western Caucasus and was described (Reitter 1909) and further recorded (Coiffait 1967(Coiffait , 1978 from Georgia. In Russia, this species is known from the Western and Northern Caucasus only. Its bionomics are barely known, but based on a few records (Solodovnikov 1998; NHMD) it can be found in leaf litter.

Quedius (Microsaurus) fulgidus (Fabricius, 1793) Fig. 14G-I
Quedius fulgidus is widely distributed in the West Palearctic and it is one of several cosmopolitan Quedius introduced to North and South America, Oriental region, Australia and New Zealand (Herman 2001). In Russia, however, its wide range stretches only through its European part to East Siberia. Quedius fulgidus is not recorded from the Russian Far East. Its microhabitats vary from leaf litter and similar ground based debris to decaying wood. It can also be found in caves (Jeannel and Jarrige 1949;Bordoni 1982), ant nests (Shulaev and Bogdanov 2008), and is overall common in synanthropic habitats (Solodovnikov 2012b).

Quedius (Microsaurus) invreae Gridelli, 1924
Figs 6D, 14M-O Based on Assing (2019), distribution of this species needs clarification because of the earlier confusion with Q. puncticollis. It is reliably known from southern Europe and Transcaucasia and presumably it is a widespread species in the south-westrn Palaearctic where it was erroneously recorded as Q. puncticollis. In Russia, it is also known from the southern regions of its European part. Its bionomics is poorly known, but apparently (Assing 2019) it is not a nidicolous species, unlike Q. puncticollis. Based on a few records from Russia provided here, it can be found in leaf litter.

*Quedius (Microsaurus) kvashei Khachikov, 2005
Quedius kvashei was described based on a single male specimen from Rostov Province (Khachikov 2005). The author indicated that the species is very similar to Q. infuscatus, from which it can be distinguished by unicolorous coloration of elytra and the structure of aedeagus. We have examined the holotype of Q. kvashei and it is clear that the species is identical with Q. infuscatus. We will formally introduce this synonymy in a separate paper treating the entire Q. infuscatus group of species, which is currently in preparation. Russia: VOLGO-DON (Khachikov 2005).

Quedius (Microsaurus) longicornis Kraatz, 1857
The species is widely distributed in Europe, but not common (Solodovnikov 2012b). In Russia, it is known mainly from its European part with the easternmost record from the South-West Siberian region. Records from the Caucasus are ambiguous and need confirmation. Usually it can be found in forests: in leaf litter, decaying wood. Also, it was found in caves (Jeannel and Jarrige 1949) and in mole (Potockaja 1967;Osella and Zanetti 1975;Nowosad 1990) and other small mammals (Solodovnikov 2012b) nests. Russia: CN EUR RU (Semionenkov et al. 2015;ZMMU); EUR S-TAIGA RU (Dedykhin et al. 2005); MDL URAL (Belskaya and Kolesnikova 2011); MDL VOLGA (Shulaev and Bogdanov 2008;Matveev 2011;Semenov et al. 2013);N CAUC (Khachikov 1998;Solodovnikov 1998;ZIN); NW EUR RU (cRyv); SW SIBER (Buhkalo et al. 2012; ZMMU); unspecified localities: 'Kaukasus' (Horion 1965); northern part of European Russia (Silfverberg 1992). Fig. 11R-T The species was hitherto known from the original description based on material from Sweden (Palm 1973). Here we report the first record of this species from Russia, where it was collected in the village Cherbi (Tuva Republic) at an elevation of ~800 m. Presumably it is a widespread boreal species.

Quedius (Microsaurus) mesomelinus (Marsham, 1802) Figs 6C, 13M-O
Quedius mesomelinus is a widely distributed transpalearctic species, which has been introduced to Greenland, North and South America and to the Australian region. It is considered boreo-montane and is confined to the northern part of the Palearctic and to the mountains in the south (Herman 2001;Solodovnikov 2012b). In Russia, it is distributed from the European part to the Far East but not recorded from the southern regions. Quedius mesomelinus can be found in forested and open landscapes, in various ground debris, sometimes in caves (Bordoni and Oromi 1998;Outerelo et al. 1998), in mammal nests or burrows (Nowosad 1990), in ant nests (Goreslavets 2016), on fungi (Voitenkova 2016;cRyv) and in basements or other shady human constructions (Ryabukhin 1999;Solodovnikov 2012b).
Notes: Veselova and Ryvkin (1991) recorded Q. sp. nov. pr. microps from Krasnoyarsk region of Russia, but examination of that material is needed to clarify the identity of that species. Fig. 14J-L This nidicolous species, confined to mole nests, is distributed in Europe, except its northern part, and in North Africa. It is more common in the western part of its range (Solodovnikov 2012b). There is only one dubious record from European Russia for Q. nigrocaeruleus (Potockaja 1976), but unfortunately without any locality data.
Based on Assing (2019), distribution of this species needs clarification because of the earlier confusion with Q. invreae. It is reliably known from the northern part of Central Europe and presumably it is less widespread species than Q. puncticollis. It is a nidicolous species that prefers mammal nests (Osella and Zanetti 1975;Nowosad 1990;Semenov et al. 2015;Assing 2019). The Russian records of this species where it was reported throughout its European part, West Siberia and from Kuznetsky Altai, need revision.
Russia: CN EUR RU (cRyv); EUR S-TAIGA RU (Dedykhin et al. 2005); KUZN ALTAI (Zinchenko 2003); MDL VOLGA ; N CAUC (Bolov 1969 a, b;Solodovnikov 2002a); NE EUR RU (Mannerheim 1830, 1831); SW SI-BER (Buhkalo et al. 2012); VOLGO-DON (Grebennikov 2001;Khachikov 2012;Sazhnev and Halilov 2015;Arzanov 2016); unspecified locality in northern part of European Russia (Silfverberg 1992). The species is distributed throughout Europe but is quite rare; it is not recorded from North Africa (Solodovnikov 2012b). In Russia, it is known from its European part, but also recorded from Irkutsk Province. Usually, it can be found in decaying wood debris from holes of old trees (Legner and Moore 1977;Owen 1999Owen , 2000Semenov 2009), often in association with ants. Russia: CN EUR RU (Semenov 2009;Semionenkov et al. 2015; ZIN); CS EUR RU   (Nordmann 1837); 'Kaukasus' (Horion 1965); 'north west and south west [Russia]' (Potockaja 1967); northern part of European Russia (Silfverberg 1992). Khachikov (2005) described Q. sofiri based on a single female specimen from Rostov Province. He compared Q. sofiri with Q. infuscatus, from which it can be distinguished by unicolorous coloration and punctation of elytra. Also he mentioned that Q. sofiri differs from Q. kvashei (described in the same paper, here placed in synonymy with Q. infuscatus) by the wider (1.5-2 times as wide as long) penultimate antennal segments and sparser punctation of scutellum (only 2-3 punctures) and elytra. We examined the holotype of Q. sofiri and verified that the diagnostic characters indicated by Khachikov (2005) for Q. sofiri are accurate. Also we were able to examine one male specimen from Northern Turkey which is identical in external morphology to the holotype of Q. sofiri. A full redescription of Q. sofiri will be provided in our separate paper, which is in preparation. Here we provide the first illustrations of the aedeagus for this species based on the specimen from Turkey (Fig. 11W-Y).

*Quedius (Microsaurus) tetrapunctatus Coiffait, 1977
Russia: VOLGO-DON (Khachikov 1998). Fig. 11I-K This species is widely distributed in Europe, especially Central Europe, but not common and the records are very scattered (Solodovnikov 2012b). In Russia, it is known only based on the literature record from the lowlands of the Middle Volga region (Goreslavets et al. 2002). The species usually can be found in debris and holes of old trees; its detailed biology is described in Sörensson (1996). Russia: MDL VOLGA (Goreslavets et al. 2002); unspecified locality: 'Nordrussl., Südrussland' (Horion 1965).

Quedius (Microsaurus) vexans Eppelsheim, 1881 Fig. 13V-X
The species is quite rare and occurs mainly in Central Europe. In Russia, it is also known mainly from its European part, but also recorded from Krasnoyarsk region in Khakassia Republic (Janovsky et al. 1998). Quedius vexans prefers the nests of small mammals (Smetana 1957;Potockaja 1967;Nowosad 1990).

Quedius (Microsaurus) xanthopus Erichson, 1839 Fig. 13Y-AA
The species is widespread in the Palearctic, but in East Siberia and Russian Far East it is known only from old literature records, which need verification. Quedius xanthopus usually can be found in decaying wood or under bark (Legner and Moore 1977;Semenov 2009;Semenov et al. 2015), often on fungi (Hågvar 1999;Vinogradova et al. 2010).

Philonthus boops tauricus
Quedius boops is a transpalearctic species distributed from Europe to the Russian Far East (Herman 2001;Solodovnikov 2012b). In Russia, it occurs everywhere, but is more common in its European part and becomes more rare towards the east, where its easternmost record is known from Lower Amur region. The species inhabits various wet ground based debris such as leaf litter, moss, hay, plant residues in forested and open landscapes (Solodovnikov 2012b; material examined here). Further comments on the identity and composition of the Q. boops-group of species are provided in the introductory Taxonomy section.
Notes: Quedius acuminatus was described from the unspecified locality 'Kaukasus' (Hochhuth 1849). Later the species was recorded from the Central and South Europe, Turkey, Armenia and Lebanon (Fauvel 1874;Horion 1965;Coiffait 1967Coiffait , 1978, but never from Russia. In our revision of the Middle Asian Quedius (Salnitska and Solodovnikov 2018b) records of Q. acuminatus from that region were recognized as doubtful. Quedius acuminatus undoubtedly belongs to the Q. boops group, but as indicated in the discussion about that group in the introductory Taxonomy section here, the borders between species there need clarification. Presumably, Q. acuminatus is a synonym of one of the currently recognized species in that group. Its type material, therefore, must be considered in a comprehensive revision of Q. boops and alike. Fig. 18G-I This brachypterous species is currently known only from the holotype from the Caucasus (Coiffait 1967), for which there is no clear locality or bionomic data. It may well be that it does not occur in Russia. Details about the type specimen, redescription, and comparison of the species can be found in Solodovnikov (2004).

[Quedius (Raphirus) cincticollis Kraatz, 1857] Fig. 16Q-S
This montane species is known from the European mountains such as eastern Alps, Carpathians, and north-western Balkans (Solodovnikov 2012b). Russian records from Kuznetksy Altai and North Eastern European regions are questionable. The species can be found in leaf litter and other kinds of ground debris of montane forests, usually around the timber line (Solodovnikov 2012b). Russia: KUZN ALTAI (Babenko 1991); NE EUR RU (Shilov 1975).

Quedius (Raphirus) fumatus (Stephens, 1833)
The species is distributed in Europe and North Africa, and is most common in the western part of its distribution (Solodovnikov 2012b). In Russia, it is known only from its European part. Quedius fumatus can be found in leaf litter or other kinds of groundbased debris in deciduous forests, often in rotten logs or under bark (Legner and Moore 1977;Owen 2000); it has been also recorded from a cave (Outerelo et al. 1998).
The species is endemic to the north-western Caucasus (south-western Russia and western Georgia) (Eppelsheim 1889;Solodovnikov 2004) where it is very common throughout its narrow distribution range. Usually it is found in leaf litter of forests from the foothills up to 1200-1500 m (Solodovnikov 2004;material examined here). Details about the taxonomy of this species can be found in Solodovnikov (2004).

[Quedius (Raphirus) humeralis Stephens, 1832] Fig. 17M-O
Quedius humeralis is a widespread West Palearctic species known from Europe, North Africa, and the Middle East (Herman 2001). The literature-based record from Mid-dle Asia (Eppelsheim 1892) was not confirmed in our recent revision (Salnitska and Solodovnikov 2018b). We have not seen any specimens from Russia, which suggests that all literature records below are based on misidentifications. The species is not common and can be found in leaf litter and different types of ground based debris (Solodovnikov 2012b).

Quedius (Raphirus) humosus Solodovnikov, 2005
The species was described from Abkhazia (Solodovnikov 2005). Here we record it for the first time from adjacent Krasnodar Territory in Russia. Specimens from the original description were collected by pitfall traps at low elevations in the mountains (Solodovnikov 2005).
Quedius korgeanus is a widely distributed species in the mountains of northern Turkey and Transcaucasia (Solodovnikov 1998(Solodovnikov , 2004. In Russia, it is known from the northwestern Caucasus with the north-easternmost records reaching Karachaevo-Cherkessia. This polytopic montane species can be found at 1400-2500 m, from forests up to alpine meadows. Quedius korgeanus occurs in forest leaf litter and other ground-based debris, under stones, in moss around streams and at edges of snowfields, etc. (Solodovnikov 2004).

Fig. 18V-X
Quedius lateralis is widely distributed in Europe and Asia Minor (Solodovnikov 2012b). It is very similar to the more south-eastern species Q. suramensis, but the south-eastern distributional border for Q. lateralis is unclear and thereby it is unknown whether these species could be sympatric. Nevertheless, there are two records of Q. lateralis from Russia, but both are questionable. The first, from the western Caucasus (Rouball 1911) could easily be a misidentified Q. suramensis, even though the author recorded Q. suramensis from the same locality as well. The second record is general from the "Identification key of the rove beetle larvae of the European part of USSR" (Potockaja 1967). We did not find any specimens from Russia in collections, which suggests that this species does not occur here. Russia (doubtful records): N CAUC (Roubal 1911); unspecified locality: 'Palearctic, decaying plant residues' (Potockaja 1967).

Quedius (Raphirus) lucidulus Erichson, 1839
Figs 7A, 16K-M The species is widespread and common in Europe and also recorded from Asia Minor (Coiffait 1978;Ghahari et al. 2009;Samin et al. 2011). Records from the Caucasus require confirmation. In Russia it is known only from its European part. Usually Q. lucidulus occurs in various ground-based debris from lowlands up to the subalpine zone (Solodovnikov 2012b).
The species is common in Europe, where it is more abundant in the central and southern regions (Solodovnikov 2012b). The absence of this common European species in the better sampled European part of Russia make the few literature records from Eest Russia highly ambiguous. Quedius maurorufus can be found in forests and open landscapes in various ground based debris.
Russia: CN EUR RU (Horion 1965;Semionenkov et al. 2015); NW EUR RU (Horion 1965); unspecified localities: 'Kaucasus' (Horion 1965); northern part of European Russia (Silfverberg 1992). Fig. 17D-F The species is known from Europe where it is more abundant in the west; it is not recorded from North Africa (Solodovnikov 2012b). In Russia, it is known from its European part and Irkutsk Province based on a few literature records. Quedius nigriceps occurs in wet ground-based habitats in forests and is also recorded from mole nests (Nowosad 1990).

Quedius (Raphirus) nitipennis (Stephens, 1833)
Quedius nitipennis is a West Palearctic species, known from Europe, North Africa, and Asia Minor (Herman 2001;Solodovnikov 2012b). In Russia, it is not common and known from scattered literature records from its European part including Northern Caucasus. Very old records from Irkutsk province (Fauvel 1874(Fauvel , 1875 are not reliable. Quedius nitipennis usually can be found at different elevations from lowlands up to 2700 m, where it inhabits wet ground-based debris around water bodies or edges of snowfields (Solodovnikov 2012b). In the southern edge of its distribution range, the species occurs at high elevations (Horion 1965;Solodovnikov 2004).

Quedius (Raphirus) obliqueseriatus Eppelsheim, 1889
Figs 8A, 18G-L This is endemic species to the north-western Caucasus and usually can be found in forest leaf litter from the foothills up to 1950 m (Solodovnikov 2004; material examined here). Records from Turkey and Iran (Korge 1964(Korge , 1971) are based on misidentifications.

Quedius (Raphirus) persimilis Mulsant & Rey, 1876
The species is widely distributed throughout Europe and is most common in central Europe (Solodovnikov 2012b). In Russia it is known only from its European part. Quedius persimilis is confined to dry and sunny open biotopes, found in ground-based debris or pine leaf litter (Solodovnikov 2012b).

Quedius (Raphirus) riparius Kellner, 1843
Figs 7B, 16T-V Quedius riparius is a ripicolous species that usually occurs at medium elevations in the mountains of Central and Southern Europe, Caucasus, Asia Minor, and Near East (Solodovnikov 2012b). In Russia this species is known only from the Western Caucasus. Generally, Q. riparius prefers wet debris around flowing water: small rivers, streams, waterfalls, often in moss (Herman 1911; material examined here).

Quedius (Raphirus) scintillans (Gravenhorst, 1806)
Quedius semiobscurus is a common West Palearctic species that occurs in Europe, North Africa, and the Middle East (Herman 2001;Anlaş and Newton 2010;Assing 2016). In Russia, it is recorded only from lower elevations of the Caucasus (Solodovnikov 1998(Solodovnikov , 2004. Usually it can be found at low elevations below 500 m, where it occurs in ground-based debris of both open and forested landscapes (Solodovnikov 2012b).

Quedius (Raphirus) sublimbatus Mäklin, 1853
Figs. 7D, 17P-R Quedius sublimbatus, described from North America, is a Holarctic species that is more common in the northern parts of its distribution, while in the southern areas it occurs in the mountains. Apparently, it has an arctoboreoalpine type of distribution (Herman 2001;Ryabukhin 1999). In Russia, Q. sublimbatus is distributed from Murmansk Province to Kamchatka peninsula and is most common in northern Siberia and Far East. The species prefers wet habitats and usually can be found in various plant debris, mosses and lichens near water (Ryabukhin 1999; material examined here).
Notes: There is some controversy whether Quedius arcticus Munster, 1921 is a synonym of Q. sublimbatus, or a valid species. Quedius arcticus was described from Norway (Munster 1921) and recorded mainly from northern Europe (Munster 1923;Palm 1963;Coiffait 1978), but also from Siberia, Mongolia (Smetana 1963(Smetana , 1967(Smetana , 1975 and North America (Smetana 1965(Smetana , 1971. Smetana (1965) synonymized Q. arcticus with Q. sublimbatus because he considered their aedeagi identical. Also he indicated that for the material from northern Europe and Mongolia as well. It remains unclear from his publication though, whether he examined the type material of Q. arcticus. In spite of Smetana's (1965) synonymy, Coiffait (1978) still used Q. arcticus as a valid name without any comments, while Veselova and Ryvkin (1991) explicitly reinstated Q. arcticus from synonymy. They mentioned that the Palearctic specimens, which they attributed to Q. arcticus, differ from the North American Q. sublimbatus in the structure of paramere. But it remains unclear whether Veselova and Ryvkin (1991) actually examined the North American specimens of Q. sublimbatus as well, or based their idea of that species only on Smetana (1975). And obviously they did not examine any type material too. Smetana (1995) again insisted on the synonymy of both species, contrary to Coiffait (1978), but he overlooked and did not comment the publication by Veselova and Ryvkin (1991). Currently Q. arcticus is listed as a junior synonym of Q. sublimbatus in all modern catalogues. We were able to examine rather wide material from Eurasia and North America and did not notice any hiatus between samples from respective continents. Moreover, the variability seen across the Holarctic material displays a pattern more complex than the division between North American and Eurasian populations, as claimed in Veselova and Ryvkin (1991). Additinally, the specimens of Q. sublimbatus from Siberia and Russian Far East are mostly wingless, usually without palisade fringe on tergite VII and with short, but differently sized wings and elytra, while the specimens from Europe and North America are winged. Interestingly, one specimen from Lower Amur region in Far East had fully developed wings.
We suspect that with a closer study including molecular analysis of the broad material and study of types, a wide-spread and wing polymorphic Holarctic Q. sublimbatus may not be the case, whereas species borders may not necessarily coincide with the border between North America and Eurasia as hypothesized by Veselova and Ryvkin (1991). For the time being and in agreement with the majority of papers, we follow Smetana' (1965) concept of the wide-spread Q. sublimbatus with Q. arcticus as its junior synonym.
The species is distributed in Western Caucasus, Transcaucasia, and northern Turkey (Herman 2001;Solodovnikov 2004;Özgen et al. 2016). In Russia, it is mainly known from Northern Caucasus region, but recently it was recorded from Middle Volga region too. Mostly, Quedius suramensis is confined to mountain forests at elevations from 200 to 1800 m, where it can be found in leaf litter, rotten mushrooms, faeces of brown bear (Solodovnikov 2002a) and even in rodent burrows (Lyayster 1967). Detailed information about this species can be found in Solodovnikov (2002a).
Quedius umbrinus is a widely distributed West Palearctic species known from Europe, Middle East, and Middle Asia, but not recorded from North Africa (Herman 2001;Assing 2013Assing , 2017bSalnitska and Solodovnikov 2018b). In Russia, it is most common throughout the European part, becoming more rare towards the east; easternmost records are from Krasnoyarsk and South-Western Siberia (material examined here). This species prefers forested landscapes and usually can be found in rather wet habitats around water in leaf litter, moss, or other ground-based debris.
The species is widely distributed in the Caucasus from its north-western part to eastern Transcaucasia, and also occurs in northern Turkey (Korge 1964(Korge , 1971Solodovnikov 1998Solodovnikov , 2002a. Quedius vulneratus can be found in moist ground based debris including rotten mushrooms and animal faeces (Solodovnikov 2002a), and under stones at the edges of snowfields. It is recorded from the foothills at 300-400 m up to the subalpine zone at 2000-2400 m elevation.

Subgenus Velleius Leach, 1819
Quedius (Velleius) dilatatus Leach, 1819 Fig. 18Y-AA The species is distributed throughout the Palearctic, from Europe to the Far East including Japan, eastern China, southern Korea, and Russia (Herman 2001; material examined here). It is associated with nests of Vespa crabro, where its larvae feed on larvae of Diptera in the nest debris. Details on biology and the developmental stages of Q. dilatatus can be found in Strassen (1957).
Notes: Overall, the subgenus Velleius comprises nine species distributed in China and Japan (Zhao and Zhou 2015;Smetana 2018) and only one species, Q. dilatatus, is widespread in the rest of the Palearctic from the Russian Far East to Europe. It seems possible, however, that broader sampling will reveal some of the Chinese or Japanese species in the Russian Far East.

Incertae sedis *Quedius fulvipennis Hochhuth, 1851
Hochhuth (1851) described Q. fulvipennis from the unclear locality "Dahuria" (historical region comprising modern Buryatia Republic, Zabaikalsky territory and Amur province) without either an explicit mention of the subgenus it belongs, or information on the type material. He mentioned that systematically Q. fulvipennis is related to Q. molochinus, but in size and proportions is similar to Q. fulgidus. According to the original description, the body length of Q. fulvipennis is 2 'lin' [around 9-10 mm] and coloration of elytra is reddish-brown. From these characters and the original description it is difficult to infer even the subgenus to which this species may belong. Later, (Bernhauer and Schubert 1916;Gridelli 1924;Scheerpeltz 1933) Q. fulvipennis was included in catalogs and lists, but without examination of the type material. Therefore, the identity of this species remains unknown. Russia: unspecified locality: "Dahuria" [historical region comprising modern Buryatia Republic, Zabaikalsky territory and Amur province] (Hochhuth 1851).

Quedius of Russia, summary table
The summary Table 1 lists all species alphabetically using the same regions as in the annotated species list. Columns (regions), from left to right, are arranged geographically, roughly from north to south and from west to east. Also they are numbered from 1 to 40 (from left to right). These numbers are duplicated in the alphabetical list of the abbreviated regions in the section about geographic subdivisions of Russia, where all regions are defined. Each cell in the summary table is graphically coded to represent details about a respective distribution record. This table should facilitate visualizations of species distributions, abundance, and degree of knowledge about them.

Discussion
Based on the examination of ca. 3000 specimens of Quedius from Russia in the collections and 165 publications with their records, our review revealed 88 species of Quedius for the fauna of Russia, of which Q. fusus, Q. humosus and Q. lundbergi are recorded from the territory of Russia for the first time. On the contrary, analysis of literature and available material suggested that Q. cincticollis, Q. humeralis, Q. lateralis, Q. maurorufus, Q. nemoralis, Q. nigrocaeruleus, Q. picipes, and possibly a few other species in fact do not occur in Russia. Their records here are dubious and likely are based on misidentifications, something to check in the future through more thorough sampling. Some species earlier reported for Russia, like for example narrowly distributed Alpine species Quedius haberfelneri recorded from the European part of Russia by Horion (1965), definitely does not occur in Russia. Quedius plancus recorded from the Caucasus by Gridelli (1924) also seems an obvious misidentification. One species, Q. brachypterus, described from an uncertain locality indicated as 'Caucasus' and never recollected since then, most likely occurs in the non-Russian part of the Caucasus. As discussed in the 'Taxonomy' section and noted in detail in the Annotated Catalogue, the identities of some species need further taxonomic study, preferably involving modern methods of molecular species delimitation, because of subtle inter-specific differences and significant intra-specific variation. One good example is the Q. boops group. As can be seen from the records in the Annotated Catalogue and visual patterns in Table 1 and Figs 3, 4, our current knowledge of Quedius of Russia is still based on very scarce material.
Naturally, the European part of Russia was better sampled and studied, while only a few regions in eastern Russia received comparable attention, such as Kamchatka or Primorsky Territory. However, even in western Russia there are poorly known areas such as Kaliningrad Province. One can clearly see in Fig. 3 that biodiversity-rich areas of the southern Urals, Altai, Buryatia, or Amur regions remain very poorly explored, in fact hardly sampled at all. Figure 4 shows that the main diversity of Quedius is confined to the more humid and warm western and southern areas of Russia, while the seemingly poor faunas of the forested Amur Province or Northern Khabarovsk region are simply an artefact of limited sampling in, or lack of literature about, these areas. Such an uneven and overall poor sampling of leaf litter invertebrates across the vast territories of Russia limits our understanding of Quedius species distributions. Many species records in faunistic papers require validation by a thorough taxonomic study of their underlying material. Generally, a high quality sampling-and collections-building program is required for Russian Quedius and Staphylinidae as a whole. The large area, diverse geography, and relatively rich rove beetle fauna of Russia provide a unique opportunity to explore many questions of Palearctic biogeography. We hope our paper will stimulate further activities in this direction.